Hidden new iTunes feature: multiple speaker streaming

A commenter known only as "David" on my post about the new MiniStore in iTunes noticed a great new
feature that I'm surprised wasn't somehow worked into yesterday's keynote: multiple speaker streaming. iTunes can now
stream music to multiple AirPort Expresses, and even keep playing the music on the originating computer.

Users have been clamoring for this ability since the day the AirPort Express hit store shelves, it finally shows up
in a .0.2 iTunes update - and not a single peep about it? I guess not every new feature, option and button can claim a
coveted keynote mention, but it's good to see you TUAW readers are on your toes when we're neck-deep in news ourselves.